This invention relates to the coating of webs of paper and the like. More particularly, this invention relates to a method of applying a coating to a paper web or the like with materials which interact to form the coating.
Such interacting materials can immobilize quickly and are difficult to mix prior to application because of poor rheological flow properties before the materials are in place on the web. An object of this invention is to provide a method of mixing such ingredients when on the web so that the materials do not require delay of interaction between mixing and setting. All known methods, prior to this invention, to immobilize a pigmented coating have suffered from unacceptable rheological flow properties when the interactive ingredients are mixed prior to application. Pigmented coatings that immobilize quickly after application result in a coating with less binder migration, greater coverage of the paper fibers because of lower density, increased opacity and brightness due to more void structure of the coating.